JJONES

I Have Twin 525sc's And Was Wondering If Getting Rid Of My Circulation Pumps And Installing Crossovers Would Be A Good Idea?if So,how Would The Plumming Work With My Cmi Headers?each Exhaust Header Has 2 Water Outlets To Them!can These Type Of Headers Be Set Up To Run Dry?

Grog

JJones -
I wouldn't unless you absolutely have to. I run a water crossover on my 502 because of a supercharger install. The stock Merc setup is reliable and runs nice consistent temps. The crossover will change all of that for you and just give you something to worry about.
They may look better than the stock recirc pumps but that is it. Don't expect any HP gains.
Just my rookie opinion.

JJONES

Thanks For The Opinion,i Thought As Much,its Just That I Have 2 Sets From Another Project And Dont Know What To Do With Them!

Craig B

Hey, I was just coming on here to research this issue too!

496 Stroker motor w/Lightnings.

Same question and to expand upon it...with a crossover, how does the water get pushed around?

Help us understand!

Thanks

hillbilly24

Woithout a circ pump you relly on your sea water pump to the all the pushing. If your have closed cooling you have no choice you have to run a circ pump otherwise it will overheat period becuase there is no circulation in the closed side of the cooling sytem. If you run raw water cooling and oher factors don't dictate you running a crossover then stay the hell away from them. You will have nothing but problems with water pressure, engine temp and oil condensation. All in the name of gaining 1-2 HP that equates to oh about 0 MPH. You can't run a stat without a circ pump unless you drill bypass holes in it and that's an endless process to get right, there are other options to replace the stat like poppet valves that can work well in the right setup or you can run a gate valve. It is just not worth the nightmare to setup.

Craig B

Thanks hillbilly, I just finished reading thread after thread and see there is no good answer.

My only reason would be to clean up the front of the motor, which would be nice, but sounds like a pain in the arse. I saw your comments about the Rex deal, but I would rather get the motor running frts before taking on additional problems.

Maybe a couple of stainless lines from the stock thermo housing to the headers will make me feel better? Guess there is no cure for the big hoses?

Thanks again

vandeano

I have the crossover and I will admit it was a nightmare at first with temp and pressure problems. But all my problems where fixed as soon as I put on a pressure relief valve. My temp stays the same at 150. At least I dont have to worry about my circ. pump leaking or belt slip. Plus I now have the added benefit of cooling my outdrive by pluming my water outlet over my outdrive.

If you dont have to use a crossover I would'nt. But if you still want to it's not that big of a problem if you have a PRESSURE RELIEF VALVE. just my 2 cents

hillbilly24

If your going for looks you should look into Python hos clamps, they are sweet looking, they are basicaly a 3 piece compression fitting that use a split farrel and a 2 piece taperd threaded barrel to compress the farell around the hose, they are prett spendy though. I think the ones for the big hose off the circ pump are about 75 bucks a piece. They come in stainless or any colol powder coated aluminum you want. They also make em big enough to fit your exhuast hoses if you have and rubber in your exhuast system, those I think are about 200 a piece but they have 2 ferels in each clamp so you only need one per conection instead of two like traditional hose clamps.

hillbilly24

here's a link to their site

http://www.pi-thon.com/

Craig B

On that Rex dealio...is this what you are talking about